Solenoid valves have become a mainstay in the everyday operation of machinery. They find use in items ranging from household heating and cooling systems to automobile engines to control systems for the largest of modern construction equipment. They are particularly important in uses requiring instant response.
Solenoid valves have in recent years been designed utilizing computers to optimize the size, weight, material of construction and all other aspects that contribute to their improved usefulness in specialized applications. As the environments for these specialized applications have become increasingly hostile in recent years, valves designed for specific purposes can meet conditions in operation that involve stresses that approach the stress limitations of their design. For example, in heavy machinery applications of recent design, the valves can be subjected to high vibrational frequencies greatly exceeding those encountered in previous applications, with the result that even small design gaps resulting from machine tolerances can result in large stresses threatening the mechanical integrity of the components.
It is essential that such solenoid valves maintain their structural integrity for long periods of time, because premature failure of a solenoid valve under operating conditions has potentially serious results. Moreover, repair of a prematurely failed solenoid valve results in unanticipated maintenance and higher costs to the operator. Furthermore, loss of use of some large moving and construction equipment for even a short time can be costly.
It has been found that solenoid valves used in such equipment, installed in a standard configuration with the solenoid housing shell extending from the mounting and assembled with industry standard internal tolerances, can be subjected to conditions that cause excessive vibration, acting much like a bell vibrating on a fixed clapper, that builds up cantilever-type stress forces that result in mechanical failure of the coil and valve assembly.
Correcting this problem involves not only securing the valve train assembly to the solenoid assembly to eliminate harmful vibrations, but also accomplishing this without creating other stresses in the valve assembly. Since the process of securing the valve train assembly to the solenoid assembly entails applying pressure that compresses the solenoid assembly along its longitudinal axis, special care must be taken that the solenoid itself is not mechanically compressed and still has room within the components confining it to allow for thermal expansion without being subjected to forces that can cause windings to become broken or loosened. Moreover, the process of securing its valve train assembly to the solenoid assembly must be accomplished without requiring excessively tight machining tolerances that would greatly increase the cost of fabricating the solenoid valve. The present invention addresses these problems.
This invention provides means by which the mechanical integrity of a solenoid valve assembly can be better secured in an economical manner.
This invention provides means for reducing the possibility of vibrational stresses in a solenoid valve assembly.
This invention provides means by which compression can be applied to a solenoid valve assembly along its longitudinal axis without damage to the solenoid.
This invention also provides changes to solenoid valve assemblies that can be made to existing assemblies, in the field, without replacement of the entire assembly.
These and other aspects and advantages of this invention will become apparent upon reading this specification and studying the drawings and appended claims.